BoilerFaultCodesYour boiler's internal control board is unable to communicate with an optional secondary accessory or pump, causing the system to stop running as a safety precaution.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Additional relay control ecoTec
What causes this fault?
This fault occurs when the boiler's main control centre loses its connection to an extra electrical component, such as an external pump or specialized heating control. The most common reason is a loose connection in the internal wiring or a component failure within the electronic control board. Because the boiler can no longer coordinate with these essential external parts, it shuts down to prevent any mechanical damage.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like D.26 — no call-out fees, no surprises.
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